Orthorhombic crystal system
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In crystallography, the orthorhombic crystal system is one of the 7 lattice point groups. Orthorhombic lattices result from stretching a cubic lattice along two of its lattice vectors by two different factors, resulting in a rectangular prism with a rectangular base (a by b, which is different from a) and height (c, which is different from a and b). All three bases intersect at 90° angles. The three lattice vectors remain mutually orthogonal.
There are four orthorhombic Bravais lattices: simple orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic.
| simple orthorhombic | base-centered orthorhombic |
body-centered orthorhombic |
face-centered orthorhombic |
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The point groups (or crystal classes) that fall under this crystal system are listed below, followed by their representations in international notation and Schoenflies notation, and mineral examples.
| Name | International | Schoenflies | Example |
|---|---|---|---|
| orthorhombic bipyramidal |  |
D2h | sulfur, olivine, aragonite |
| orthorhombic pyramidal | 2mm | C2v | hemimorphite, bertrandite |
| orthorhombic sphenoidal | 222 | D2 | epsomite |
[edit] References
- Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., pp. 69 - 73, ISBN 0-471-80580-7
